# Identity and access management for AWS Transfer Family
AWS Identity and Access Management (IAM) is an AWS service that helps an administrator securely control access to AWS resources. IAM administrators control who can be *authenticated* (signed in) and *authorized* (have permissions) to use AWS Transfer Family resources. IAM is an AWS service that you can use with no additional charge.
**Topics**
+ [Audience](#security_iam_audience)
+ [Authenticating with identities](#security_iam_authentication)
+ [Managing access using policies](#security_iam_access-manage)
+ [How AWS Transfer Family works with IAM](security_iam_service-with-iam.md)
+ [AWS Transfer Family identity-based policy examples](security_iam_id-based-policy-examples.md)
+ [AWS Transfer Family tag-based policy examples](security_iam_tag-based-policy-examples.md)
+ [Troubleshooting AWS Transfer Family identity and access](security_iam_troubleshoot.md)
+ [IAM condition keys for organizational governance](transfer-condition-keys.md)
## Audience
How you use AWS Identity and Access Management (IAM) differs based on your role:
+ **Service user** - request permissions from your administrator if you cannot access features (see [Troubleshooting AWS Transfer Family identity and access](security_iam_troubleshoot.md))
+ **Service administrator** - determine user access and submit permission requests (see [How AWS Transfer Family works with IAM](security_iam_service-with-iam.md))
+ **IAM administrator** - write policies to manage access (see [AWS Transfer Family identity-based policy examples](security_iam_id-based-policy-examples.md))
## Authenticating with identities
Authentication is how you sign in to AWS using your identity credentials. You must be authenticated as the AWS account root user, an IAM user, or by assuming an IAM role.
You can sign in as a federated identity using credentials from an identity source like AWS IAM Identity Center (IAM Identity Center), single sign-on authentication, or Google/Facebook credentials. For more information about signing in, see [How to sign in to your AWS account](https://docs.aws.amazon.com/signin/latest/userguide/how-to-sign-in.html) in the *AWS Sign-In User Guide*.
For programmatic access, AWS provides an SDK and CLI to cryptographically sign requests. For more information, see [AWS Signature Version 4 for API requests](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_sigv.html) in the *IAM User Guide*.
### AWS account root user
When you create an AWS account, you begin with one sign-in identity called the AWS account *root user* that has complete access to all AWS services and resources. We strongly recommend that you don't use the root user for everyday tasks. For tasks that require root user credentials, see [Tasks that require root user credentials](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_root-user.html#root-user-tasks) in the *IAM User Guide*.
### Federated identity
As a best practice, require human users to use federation with an identity provider to access AWS services using temporary credentials.
A *federated identity* is a user from your enterprise directory, web identity provider, or Directory Service that accesses AWS services using credentials from an identity source. Federated identities assume roles that provide temporary credentials.
For centralized access management, we recommend AWS IAM Identity Center. For more information, see [What is IAM Identity Center?](https://docs.aws.amazon.com/singlesignon/latest/userguide/what-is.html) in the *AWS IAM Identity Center User Guide*.
### IAM users and groups
An *[IAM user](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_users.html)* is an identity with specific permissions for a single person or application. We recommend using temporary credentials instead of IAM users with long-term credentials. For more information, see [Require human users to use federation with an identity provider to access AWS using temporary credentials](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#bp-users-federation-idp) in the *IAM User Guide*.
An [https://docs.aws.amazon.com/IAM/latest/UserGuide/id_groups.html](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_groups.html) specifies a collection of IAM users and makes permissions easier to manage for large sets of users. For more information, see [Use cases for IAM users](https://docs.aws.amazon.com/IAM/latest/UserGuide/gs-identities-iam-users.html) in the *IAM User Guide*.
### IAM roles
An *[IAM role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html)* is an identity with specific permissions that provides temporary credentials. You can assume a role by [switching from a user to an IAM role (console)](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_use_switch-role-console.html) or by calling an AWS CLI or AWS API operation. For more information, see [Methods to assume a role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_manage-assume.html) in the *IAM User Guide*.
IAM roles are useful for federated user access, temporary IAM user permissions, cross-account access, cross-service access, and applications running on Amazon EC2. For more information, see [Cross account resource access in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies-cross-account-resource-access.html) in the *IAM User Guide*.
## Managing access using policies
You control access in AWS by creating policies and attaching them to AWS identities or resources. A policy defines permissions when associated with an identity or resource. AWS evaluates these policies when a principal makes a request. Most policies are stored in AWS as JSON documents. For more information about JSON policy documents, see [Overview of JSON policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html#access_policies-json) in the *IAM User Guide*.
Using policies, administrators specify who has access to what by defining which **principal** can perform **actions** on what **resources**, and under what **conditions**.
By default, users and roles have no permissions. An IAM administrator creates IAM policies and adds them to roles, which users can then assume. IAM policies define permissions regardless of the method used to perform the operation.
### Identity-based policies
Identity-based policies are JSON permissions policy documents that you attach to an identity (user, group, or role). These policies control what actions identities can perform, on which resources, and under what conditions. To learn how to create an identity-based policy, see [Define custom IAM permissions with customer managed policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_create.html) in the *IAM User Guide*.
Identity-based policies can be *inline policies* (embedded directly into a single identity) or *managed policies* (standalone policies attached to multiple identities). To learn how to choose between managed and inline policies, see [Choose between managed policies and inline policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies-choosing-managed-or-inline.html) in the *IAM User Guide*.
### Resource-based policies
Resource-based policies are JSON policy documents that you attach to a resource. Examples include IAM *role trust policies* and Amazon S3 *bucket policies*. In services that support resource-based policies, service administrators can use them to control access to a specific resource. You must [specify a principal](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_principal.html) in a resource-based policy.
Resource-based policies are inline policies that are located in that service. You can't use AWS managed policies from IAM in a resource-based policy.
### Access control lists (ACLs)
Access control lists (ACLs) control which principals (account members, users, or roles) have permissions to access a resource. ACLs are similar to resource-based policies, although they do not use the JSON policy document format.
Amazon S3, AWS WAF, and Amazon VPC are examples of services that support ACLs. To learn more about ACLs, see [Access control list (ACL) overview](https://docs.aws.amazon.com/AmazonS3/latest/userguide/acl-overview.html) in the *Amazon Simple Storage Service Developer Guide*.
### Other policy types
AWS supports additional policy types that can set the maximum permissions granted by more common policy types:
+ **Permissions boundaries** – Set the maximum permissions that an identity-based policy can grant to an IAM entity. For more information, see [Permissions boundaries for IAM entities](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_boundaries.html) in the *IAM User Guide*.
+ **Service control policies (SCPs)** – Specify the maximum permissions for an organization or organizational unit in AWS Organizations. For more information, see [Service control policies](https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_scps.html) in the *AWS Organizations User Guide*.
+ **Resource control policies (RCPs)** – Set the maximum available permissions for resources in your accounts. For more information, see [Resource control policies (RCPs)](https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_rcps.html) in the *AWS Organizations User Guide*.
+ **Session policies** – Advanced policies passed as a parameter when creating a temporary session for a role or federated user. For more information, see [Session policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html#policies_session) in the *IAM User Guide*.
### Multiple policy types
When multiple types of policies apply to a request, the resulting permissions are more complicated to understand. To learn how AWS determines whether to allow a request when multiple policy types are involved, see [Policy evaluation logic](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_evaluation-logic.html) in the *IAM User Guide*.
# How AWS Transfer Family works with IAM
Before you use AWS Identity and Access Management (IAM) to manage access to AWS Transfer Family, you should understand what IAM features are available to use with AWS Transfer Family. To get a high-level view of how AWS Transfer Family and other AWS services work with IAM, see [AWS services that work with IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_aws-services-that-work-with-iam.html) in the *IAM User Guide*.
**Topics**
+ [AWS Transfer Family identity-based policies](#security_iam_service-with-iam-id-based-policies)
+ [AWS Transfer Family resource-based policies](#security_iam_service-with-iam-resource-based-policies)
+ [Authorization based on AWS Transfer Family tags](#security_iam_service-with-iam-tags)
+ [AWS Transfer Family IAM roles](#security_iam_service-with-iam-roles)
## AWS Transfer Family identity-based policies
With IAM identity-based policies, you can specify allowed or denied actions and resources as well as the conditions under which actions are allowed or denied. AWS Transfer Family supports specific actions, resources, and condition keys. To learn about all of the elements that you use in a JSON policy, see [IAM JSON policy elements reference](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements.html) in the *AWS Identity and Access Management User Guide*.
### Actions
Administrators can use AWS JSON policies to specify who has access to what. That is, which **principal** can perform **actions** on what **resources**, and under what **conditions**.
The `Action` element of a JSON policy describes the actions that you can use to allow or deny access in a policy. Include actions in a policy to grant permissions to perform the associated operation.
Policy actions in AWS Transfer Family use the following prefix before the action: `transfer:`. For example, to grant someone permission to create a server, with the Transfer Family `CreateServer` API operation, you include the `transfer:CreateServer` action in their policy. Policy statements must include either an `Action` or `NotAction` element. AWS Transfer Family defines its own set of actions that describe tasks that you can perform with this service.
To specify multiple actions in a single statement, separate them with commas as follows.
```
"Action": [
"transfer:action1",
"transfer:action2"
```
You can specify multiple actions using wildcards (\$1). For example, to specify all actions that begin with the word `Describe`, include the following action.
```
"Action": "transfer:Describe*"
```
To see a list of AWS Transfer Family actions, see [Actions defined by AWS Transfer Family](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awstransferfamily.html#awstransferfamily-actions-as-permissions) in the *Service Authorization Reference*.
### Resources
Administrators can use AWS JSON policies to specify who has access to what. That is, which **principal** can perform **actions** on what **resources**, and under what **conditions**.
The `Resource` JSON policy element specifies the object or objects to which the action applies. As a best practice, specify a resource using its [Amazon Resource Name (ARN)](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference-arns.html). For actions that don't support resource-level permissions, use a wildcard (\$1) to indicate that the statement applies to all resources.
```
"Resource": "*"
```
The Transfer Family server resource has the following ARN.
```
arn:aws:transfer:${Region}:${Account}:server/${ServerId}
```
For example, to specify the `s-01234567890abcdef` Transfer Family server in your statement, use the following ARN.
```
"Resource": "arn:aws:transfer:us-east-1:123456789012:server/s-01234567890abcdef"
```
For more information about the format of ARNs, see [Amazon Resource Names (ARNs)](https://docs.aws.amazon.com/general/latest/gr/aws-arns-and-namespaces.html) in the *Service Authorization Reference*, or [IAM ARNs](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_identifiers.html#identifiers-arns) in the *IAM User Guide*.
To specify all instances that belong to a specific account, use the wildcard (\$1).
```
"Resource": "arn:aws:transfer:us-east-1:123456789012:server/*"
```
Some AWS Transfer Family actions are performed on multiple resources, such as those used in IAM policies. In those cases, you must use the wildcard (\$1).
```
"Resource": "arn:aws:transfer:*:123456789012:server/*"
```
In some cases you need to specify more than one type of resource, for example, if you create a policy that allows access to Transfer Family servers and users. To specify multiple resources in a single statement, separate the ARNs with commas.
```
"Resource": [
"resource1",
"resource2"
]
```
To see a list of AWS Transfer Family resources, see [Resource types defined by AWS Transfer Family](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awstransferfamily.html#awstransferfamily-resources-for-iam-policies) in the *Service Authorization Reference*.
### Condition keys
Administrators can use AWS JSON policies to specify who has access to what. That is, which **principal** can perform **actions** on what **resources**, and under what **conditions**.
The `Condition` element specifies when statements execute based on defined criteria. You can create conditional expressions that use [condition operators](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition_operators.html), such as equals or less than, to match the condition in the policy with values in the request. To see all AWS global condition keys, see [AWS global condition context keys](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html) in the *IAM User Guide*.
AWS Transfer Family defines its own set of condition keys and also supports using some global condition keys. To see a list of AWS Transfer Family condition keys, see [Condition keys for AWS Transfer Family](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awstransferfamily.html#awstransferfamily-policy-keys) in the *Service Authorization Reference*.
### Examples
To view examples of AWS Transfer Family identity-based policies, see [AWS Transfer Family identity-based policy examples](security_iam_id-based-policy-examples.md). For VPC endpoint-specific IAM policies, see [Limiting VPC endpoint access for Transfer Family servers](create-server-in-vpc.md#limit-vpc-endpoint-access).
## AWS Transfer Family resource-based policies
Resource-based policies are JSON policy documents that specify what actions a specified principal can perform on the AWS Transfer Family resource and under what conditions. Amazon S3 supports resource-based permissions policies for Amazon S3 *buckets*. Resource-based policies let you grant usage permission to other accounts on a per-resource basis. You can also use a resource-based policy to allow an AWS service to access your Amazon S3 *buckets*.
To enable cross-account access, you can specify an entire account or IAM entities in another account as the [principal in a resource-based policy](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_principal.html). Adding a cross-account principal to a resource-based policy is only half of establishing the trust relationship. When the principal and the resource are in different AWS accounts, you must also grant the principal entity permission to access the resource. Grant permission by attaching an identity-based policy to the entity. However, if a resource-based policy grants access to a principal in the same account, no additional identity-based policy is required. For more information, see [How IAM roles differ from resource-based policies ](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_compare-resource-policies.html)in the *AWS Identity and Access Management User Guide*.
The Amazon S3 service supports only one type of resource-based policy called a **bucket* policy*, which is attached to a *bucket*. This policy defines which principal entities (accounts, users, roles, and federated users) can perform actions on the object.
### Examples
To view examples of AWS Transfer Family resource-based policies, see [AWS Transfer Family tag-based policy examples](security_iam_tag-based-policy-examples.md).
## Authorization based on AWS Transfer Family tags
You can attach tags to AWS Transfer Family resources or pass tags in a request to AWS Transfer Family. To control access based on tags, you provide tag information in the [condition element](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html) of a policy using the `transfer:ResourceTag/key-name`, `aws:RequestTag/key-name`, or `aws:TagKeys` condition keys. For information about how to use tags to control access to AWS Transfer Family resources, see [AWS Transfer Family tag-based policy examples](security_iam_tag-based-policy-examples.md).
## AWS Transfer Family IAM roles
An [IAM role](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html) is an entity within your AWS account that has specific permissions.
### Using temporary credentials with AWS Transfer Family
You can use temporary credentials to sign in with federation, assume an IAM role, or to assume a cross-account role. You obtain temporary security credentials by calling AWS STS API operations such as [AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html) or [GetFederationToken](https://docs.aws.amazon.com/STS/latest/APIReference/API_GetFederationToken.html).
AWS Transfer Family supports using temporary credentials.
# AWS Transfer Family identity-based policy examples
By default, IAM users and roles don't have permission to create or modify AWS Transfer Family resources. They also can't perform tasks using the AWS Management Console, AWS CLI, or AWS API. An IAM administrator must create IAM policies that grant users and roles permission to perform specific API operations on the specified resources they need. The administrator must then attach those policies to the IAM users or groups that require those permissions.
To learn how to create an IAM identity-based policy using these example JSON policy documents, see [Creating policies on the JSON tab](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_create.html#access_policies_create-json-editor) in the *AWS Identity and Access Management User Guide*.
**Topics**
+ [Policy best practices](#security_iam_service-with-iam-policy-best-practices)
+ [Using the AWS Transfer Family console](#security_iam_id-based-policy-examples-console)
+ [Allow users to view their own permissions](#security_iam_id-based-policy-examples-view-own-permissions)
## Policy best practices
Identity-based policies determine whether someone can create, access, or delete AWS Transfer Family resources in your account. These actions can incur costs for your AWS account. When you create or edit identity-based policies, follow these guidelines and recommendations:
+ **Get started with AWS managed policies and move toward least-privilege permissions** – To get started granting permissions to your users and workloads, use the *AWS managed policies* that grant permissions for many common use cases. They are available in your AWS account. We recommend that you reduce permissions further by defining AWS customer managed policies that are specific to your use cases. For more information, see [AWS managed policies](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_managed-vs-inline.html#aws-managed-policies) or [AWS managed policies for job functions](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies_job-functions.html) in the *IAM User Guide*.
+ **Apply least-privilege permissions** – When you set permissions with IAM policies, grant only the permissions required to perform a task. You do this by defining the actions that can be taken on specific resources under specific conditions, also known as *least-privilege permissions*. For more information about using IAM to apply permissions, see [ Policies and permissions in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies.html) in the *IAM User Guide*.
+ **Use conditions in IAM policies to further restrict access** – You can add a condition to your policies to limit access to actions and resources. For example, you can write a policy condition to specify that all requests must be sent using SSL. You can also use conditions to grant access to service actions if they are used through a specific AWS service, such as CloudFormation. For more information, see [ IAM JSON policy elements: Condition](https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_elements_condition.html) in the *IAM User Guide*.
+ **Use IAM Access Analyzer to validate your IAM policies to ensure secure and functional permissions** – IAM Access Analyzer validates new and existing policies so that the policies adhere to the IAM policy language (JSON) and IAM best practices. IAM Access Analyzer provides more than 100 policy checks and actionable recommendations to help you author secure and functional policies. For more information, see [Validate policies with IAM Access Analyzer](https://docs.aws.amazon.com/IAM/latest/UserGuide/access-analyzer-policy-validation.html) in the *IAM User Guide*.
+ **Require multi-factor authentication (MFA)** – If you have a scenario that requires IAM users or a root user in your AWS account, turn on MFA for additional security. To require MFA when API operations are called, add MFA conditions to your policies. For more information, see [ Secure API access with MFA](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_mfa_configure-api-require.html) in the *IAM User Guide*.
For more information about best practices in IAM, see [Security best practices in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html) in the *IAM User Guide*.
## Using the AWS Transfer Family console
To access the AWS Transfer Family console, you must have a minimum set of permissions. These permissions must allow you to list and view details about the AWS Transfer Family resources in your AWS account. If you create an identity-based policy that is more restrictive than the minimum required permissions, the console won't function as intended for entities (IAM users or roles) with that policy. For more information, see [Adding permissions to a user](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_users_change-permissions.html#users_change_permissions-add-console) in the *AWS Identity and Access Management User Guide*.
You don't need to allow minimum console permissions for users that are making calls only to the AWS CLI or the AWS API. Instead, allow access to only the actions that match the API operation that you're trying to perform.
## Allow users to view their own permissions
This example shows how you might create a policy that allows IAM users to view the inline and managed policies that are attached to their user identity. This policy includes permissions to complete this action on the console or programmatically using the AWS CLI or AWS API.
```
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "ViewOwnUserInfo",
"Effect": "Allow",
"Action": [
"iam:GetUserPolicy",
"iam:ListGroupsForUser",
"iam:ListAttachedUserPolicies",
"iam:ListUserPolicies",
"iam:GetUser"
],
"Resource": ["arn:aws:iam::*:user/${aws:username}"]
},
{
"Sid": "NavigateInConsole",
"Effect": "Allow",
"Action": [
"iam:GetGroupPolicy",
"iam:GetPolicyVersion",
"iam:GetPolicy",
"iam:ListAttachedGroupPolicies",
"iam:ListGroupPolicies",
"iam:ListPolicyVersions",
"iam:ListPolicies",
"iam:ListUsers"
],
"Resource": "*"
}
]
}
```
# AWS Transfer Family tag-based policy examples
The following are examples of how to control access to AWS Transfer Family resources based on tags.
## Using tags to control access to AWS Transfer Family resources
Conditions in IAM policies are part of the syntax that you use to specify permissions to AWS Transfer Family resources. You can control access to AWS Transfer Family resources (such as users, servers, roles, and other entities) based on tags on those resources. Tags are key-value pairs. For more information about tagging resources, see [Tagging AWS resources](https://docs.aws.amazon.com/general/latest/gr/aws_tagging.html) in the *AWS General Reference*.
In AWS Transfer Family, resources can have tags, and some actions can include tags. When you create an IAM policy, you can use tag condition keys to control the following:
+ Which users can perform actions on an AWS Transfer Family resource, based on tags that the resource has.
+ What tags can be passed in an action's request.
+ Whether specific tag keys can be used in a request.
By using tag-based access control, you can apply finer control than at the API level. You also can apply more dynamic control than by using resource-based access control. You can create IAM policies that allow or deny an operation based on tags provided in the request (request tags). You can also create IAM policies based on tags on the resource that is being operated on (resource tags). In general, resource tags are for tags that are already on resources, request tags are for when you're adding tags to or removing tags from a resource.
For the complete syntax and semantics of tag condition keys, see [Controlling access to AWS resources using resource tags](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_tags.html) in the *IAM User Guide*. For details about specifying IAM policies with API Gateway, see [Control access to an API with IAM permissions](https://docs.aws.amazon.com/apigateway/latest/developerguide/permissions.html) in the *API Gateway Developer Guide*.
### Example 1: Deny actions based on resource tags
You can deny an action to be performed on a resource based on tags. The following example policy denies `TagResource`, `UntagResource`, `StartServer`, `StopServer`, `DescribeServer`, and `DescribeUser` operations if the user or server resource is tagged with the key `stage` and the value `prod`.
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Deny",
"Action": [
"transfer:TagResource",
"transfer:UntagResource",
"transfer:StartServer",
"transfer:StopServer",
"transfer:DescribeServer",
"transfer:DescribeUser"
],
"Resource": "*",
"Condition": {
"StringEquals": {
"aws:ResourceTag/stage": "prod"
}
}
}
]
}
```
### Example 2: Allow actions based on resource tags
You can allow an action to be performed on a resource based on tags. The following example policy allows `TagResource`, `UntagResource`, `StartServer`, `StopServer`, `DescribeServer`, and `DescribeUser` operations if the user or server resource is tagged with the key `stage` and the value `prod`.
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": [
"transfer:TagResource",
"transfer:UntagResource",
"transfer:StartServer",
"transfer:StopServer",
"transfer:DescribeServer",
"transfer:DescribeUser"
],
"Resource": "*",
"Condition": {
"StringEquals": {
"aws:ResourceTag/stage": "prod"
}
}
}
]
}
```
### Example 3: Deny creation of a user or server based on request tags
The following example policy contains two statements. The first statement denies the `CreateServer` operation on all resources if the cost center key for the tag doesn't have a value.
The second statement denies the `CreateServer` operation if the cost center key for the tag contains any other value besides 1, 2 or 3.
**Note**
This policy does allow creating or deleting a resource that contains a key called `costcenter` and a value of `1`, `2`, or `3`.
****
```
{
"Version":"2012-10-17",
"Statement": [
{
"Effect": "Deny",
"Action": [
"transfer:CreateServer"
],
"Resource": [
"*"
],
"Condition": {
"Null": {
"aws:RequestTag/costcenter": "true"
}
}
},
{
"Effect": "Deny",
"Action": "transfer:CreateServer",
"Resource": [
"*"
],
"Condition": {
"ForAnyValue:StringNotEquals": {
"aws:RequestTag/costcenter": [
"1",
"2",
"3"
]
}
}
}
]
}
```
# Troubleshooting AWS Transfer Family identity and access
Use the following information to help you diagnose and fix common issues that you might encounter when working with AWS Transfer Family and IAM.
**Topics**
+ [I am not authorized to perform an action in AWS Transfer Family](#security_iam_troubleshoot-no-permissions)
+ [I am not authorized to perform iam:PassRole](#security_iam_troubleshoot-passrole)
+ [I want to allow people outside of my AWS account to access my AWS Transfer Family resources](#security_iam_troubleshoot-cross-account-access)
## I am not authorized to perform an action in AWS Transfer Family
If the AWS Management Console tells you that you're not authorized to perform an action, then you must contact your administrator for assistance. Your administrator is the person that provided you with your sign-in credentials.
The following example error occurs when the `mateojackson` IAM user tries to use the console to view details about a *widget* but does not have `transfer:GetWidget` permissions.
```
User: arn:aws:iam::123456789012:user/mateojackson is not authorized to perform: transfer:GetWidget on resource: my-example-widget
```
In this case, Mateo asks his administrator to update his policies to allow him to access the `my-example-widget` resource using the `transfer;:GetWidget` action.
## I am not authorized to perform iam:PassRole
If you receive an error that you're not authorized to perform the `iam:PassRole` action, your policies must be updated to allow you to pass a role to AWS Transfer Family.
Some AWS services allow you to pass an existing role to that service instead of creating a new service role or service-linked role. To do this, you must have permissions to pass the role to the service.
The following example error occurs when an IAM user named `marymajor` tries to use the console to perform an action in AWS Transfer Family. However, the action requires the service to have permissions that are granted by a service role. Mary does not have permissions to pass the role to the service.
```
User: arn:aws:iam::123456789012:user/marymajor is not authorized to perform: iam:PassRole
```
In this case, Mary's policies must be updated to allow her to perform the `iam:PassRole` action.
If you need help, contact your AWS administrator. Your administrator is the person who provided you with your sign-in credentials.
The following example policy contains the permission to pass a role to AWS Transfer Family. Replace **123456789012** with your AWS account ID and **MyTransferRole** with your actual IAM role name.
****
```
{
"Version":"2012-10-17",
"Statement": [
{ "Action": "iam:PassRole",
"Resource": "arn:aws:iam::123456789012:role/MyTransferRole",
"Effect": "Allow"
}
]
}
```
## I want to allow people outside of my AWS account to access my AWS Transfer Family resources
You can create a role that users in other accounts or people outside of your organization can use to access your resources. You can specify who is trusted to assume the role. For services that support resource-based policies or access control lists (ACLs), you can use those policies to grant people access to your resources.
To learn more, consult the following:
+ To learn whether AWS Transfer Family supports these features, see [How AWS Transfer Family works with IAM](security_iam_service-with-iam.md).
+ To learn how to provide access to your resources across AWS accounts that you own, see [Providing access to an IAM user in another AWS account that you own](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_common-scenarios_aws-accounts.html) in the *IAM User Guide*.
+ To learn how to provide access to your resources to third-party AWS accounts, see [Providing access to AWS accounts owned by third parties](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_common-scenarios_third-party.html) in the *IAM User Guide*.
+ To learn how to provide access through identity federation, see [Providing access to externally authenticated users (identity federation)](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_common-scenarios_federated-users.html) in the *IAM User Guide*.
+ To learn the difference between using roles and resource-based policies for cross-account access, see [Cross account resource access in IAM](https://docs.aws.amazon.com/IAM/latest/UserGuide/access_policies-cross-account-resource-access.html) in the *IAM User Guide*.
# IAM condition keys for organizational governance
AWS Transfer Family provides IAM condition keys that allow you to restrict resource configurations in any IAM policy. These condition keys can be used in identity-based policies attached to users or roles, or Service Control Policies (SCPs) for organizational governance.
Service Control Policies are IAM policies that apply to an entire AWS organization, providing preventative guardrails across multiple accounts. When used in SCPs, these condition keys help enforce security and compliance requirements organization-wide.
**See also**
+ [Actions, resources, and condition keys for Transfer Family](https://docs.aws.amazon.com/service-authorization/latest/reference/list_awstransferfamily.html)
+ [Service control policies (SCPs)](https://docs.aws.amazon.com/organizations/latest/userguide/orgs_manage_policies_scps.html)
+ Video describing how to enforce preventive guardrails using service control policies
[](http://www.youtube.com/watch?v=https://www.youtube.com/embed/mEO05mmbSms)
## Available condition keys
AWS Transfer Family supports the following condition keys for use in IAM policies:
`transfer:RequestServerEndpointType`
Restricts server creation and updates based on endpoint type (PUBLIC, VPC, VPC\$1ENDPOINT). Commonly used to prevent public-facing endpoints.
`transfer:RequestServerProtocols`
Restricts server creation and updates based on supported protocols (SFTP, FTPS, FTP, AS2).
`transfer:RequestServerDomain`
Restricts server creation based on domain type (S3, EFS).
`transfer:RequestConnectorProtocol`
Restricts connector creation based on protocol (AS2, SFTP).
## Supported actions
The condition keys can be applied to the following AWS Transfer Family actions:
+ `CreateServer`: Supports `RequestServerEndpointType`, `RequestServerProtocols`, and `RequestServerDomain` condition keys
+ `UpdateServer`: Supports `RequestServerEndpointType` and `RequestServerProtocols` condition keys
+ `CreateConnector`: Supports `RequestConnectorProtocol` condition key
## Example SCP policy
The following example SCP prevents the creation of public AWS Transfer Family servers across your organization:
****
```
{
"Version":"2012-10-17",
"Statement": [{
"Sid": "DenyPublicTransferServers",
"Effect": "Deny",
"Action": ["transfer:CreateServer", "transfer:UpdateServer"],
"Resource": "*",
"Condition": {
"StringEquals": {
"transfer:RequestServerEndpointType": "PUBLIC"
}
}
}]
}
```